Ue-WPIoT is suffering from the limited communication range, which is mainly constrained by the WET range. The fundamental limitation of the WET range lies in much higher threshold for energy harvesting (EH) than that for information decoding [1]}. The advent of energy beam-forming (BF) technology brings opportunities to overcome this limitation. In particular, the UAV employing a BF antenna can generate the BF energy toward a certain direction. The focused energy can significantly extend the powering distance.
